The usual way for rechargables, I imagine. They'll handle it just fine until they die from an overly deep discharge. If the chip is very clever, then it'll det

The usual way for rechargables, I imagine. They'll handle it just fine until they die from an overly deep discharge. If the chip is very clever, then it'll detect that it's working on a rechargable (from voltage curves?), and stop discharging after a certain point. But the specifics there depend on the exact chemistry used, so it'd be difficult to get it right.